Electron discharge device



Aug. 16, 1960' A. E. OBERG ELECTRON DISCHARGE DEVICE Filed June 19, 1959so- III:

\ 54 k I L20 INVENTUR Albert 'E. Oberg 24 BY Q t un 2,949,556 PatentedAug. 16, 1960 2,949,556 ELECTRON DISCHARGE DEVICE Albert Oberg, Elmira,N .Y., assignor to Westinghouse Electric Corporation, East Pittsburgh,Pa., a corporation of Pennsylvania Filed June 19, 1959, Ser. No. 821,565'4 Claims. (Cl. 313-82) This invention relates to the mounting ofelectrode structures in envelopes and more particularly to the mountingof an electron gun structure in an envelope of a cathode ray tube.

The conventional type electron gun now used in cathode ray tubes isusually of a unitary construction. The gun consists of a plurality ofelectrodes assembled and mounted together to form a structure which maybe inserted as a whole into the envelope or neck of the cathode raytube. The gun normally consists of a plurality of spaced tubularelectrodes with their axes lying on the axis of the neck portion of thecathode ray tube. A plurality of insulating rods are positioned alongthe outer surface of the electrodes and may be parallel to the axes ofthe electrodes.

Pins or studs secured to the outer periphery of the electrodes areattached to the insulating rods. The studs are normally secured to theinsulating rod by heating the insulating rod up to a molten state andthereafter allowing the material to cool and thereby impale the studs inthe insulating rod. This provides a unitary structure of substantialstrength and the electrodes are aligned and spaced during the process ofsealing the stud members to the insulating rods. The electron gun isthen mounted to a glass stem member- Electrically conductive lead-inmembers providing means of supplying the necessary potentials to theelectrodes are sealed into the glass stem member. These lead-in membersare welded to the electrodes and also mechanically mount the gun on thestem member. The resulting assembly is inserted into the neck of thecathode ray tube and the button like stem member is sealed to the neck.The stem member is also provided with an exhaust tubulation used inprocessing the tube. The front end of the gun, that is the portionprojecting farthest into the neck, is usually provided with centeringmeans which positions the electron gun within the neck. This centeringmeans in most cases also provides an electrical contact between acoating on the interior surface of the cathode ray tube and the anode ofthe electron gun. The electron gun is supported in the neck by means ofthe lead-in members from the stem member.

It is an object of this invention to provide an improved method ofsupporting an electron gun within a cathode ray tube.

It is another object to provide an improved electron gun structure toprovide better mounting within the cathode ray tube.

It is another object to provide means of supporting the electron gunwithin the cathode ray tube without disturbing the alignment of theelectrode members of the electron gun.

It is another object of this invention to support the electron gun fromthe glass stem member without utilizing any of the electrode members.

These and other objects are effected by my invention as will be apparentfrom the following description taken in accordance with the accompanyingdrawing, throughout 2 which like reference characters indicate likeparts, and in which:

Figure 1 illustrates a cathode ray tube embodying the teachings of myinvention;

Figure 2 is an enlarged view of the electron gun mounted within the neckportion of the cathode ray tube of Fig. 1;

Figure 3 is a cross sectional view of Fig. 2 taken along the line IIIIIIof Fig. 2; and

Figure 4 is a perspective view of the electron gun shown in Fig. 1.

Referring in detail to the drawing, the cathode ray tube consists of anenvelope 12 having a neck portion 14, a flared portion '16 and a faceplate portion 18.

An electron gun 20 is assembled and mounted to a stem member 24 and isthen inserted into the neck portion 14 of the envelope 12. The stemportion may then be sealed to the neck as is shown in Fig. 2.

In the specific embodiment shown the electron gun 20 consists of acontrol grid 30, screen grid 32, and an anode 34 which are securedtogether to form a unitary structure by means of the insulating rods 40.Studs 42 are provided on the electrodes of the gun 20 and are sealed tothe insulating rods 40 as previously discussed. The end of the electrongun 20 which is farthest from the stem member 24 is centered in the neckportion 14 by means of a resilient spacer structure 39. A cathodeelectrode 31 and a heater 33 are provided in the electron gun 20 asillustrated in Fig. 3.

Positioned at the rear end of the electron gun 20 as shown in Figs. 2, 3and 4 is a ring member 50 of larger diameter than the control gridmember 30. A portion of the ring has been removed to facilitate radiofrequency treatment of parts within the ring and clearance for a highvoltage lead 41. The support ring 50 is also provided with studs 52which are sealed to the insulating members in the same process and atthe same time as the assembly of the electrode members. Three stem leadmembers 54 are welded to spaced points about the support ring 59 andsupport the electron gun 20 in the neck portion 14- with respect to thestem member 24. The ring 50 operates at the same potential as thecontrol grid 30 and therefore one of the stem leads 54 provides thenecessary potential to the control grid 30 by means of a flexibleconnector between the two members.

The two stem leads 56 illustrated in Figs. 3 and 4 provide means ofapplying the necessary potential to the heater 33 while another stemlead member 58 illustrated supplies the necessary potential to thecathode sleeve 31. The stem lead 41 supplies potential to the anode 34and a lead 60 supplies potential to the control grid 32. It can be thusseen that the support ring 50 is supported at three substantiallyequally spaced points about its periphery. The support ring 50 is inturn attached to the insulating rods 40 by studs 52 and provides supportfor the electron gun 20 from the stern member 24-. The resulting supportis extremely rugged. Extreme vibration of the tube resulting indistortion of the mount will not modify or change the spacing ofelectrodes within the gun structure. Distortion of mount structure willnot modify alignment or spacing of the electrode members of the electrongun.

While I show my invention only in one form, it will be obvious to thoseskilled in the art that it is not so limited, but is susceptible tovarious other changes and modifications without departing from thespirit and scope thereof.

I claim as my invention:

1. A cathode ray tube comprising an envelope including a neck portion,an electron gun structure to generate an electron beam, said structurecomprising in the order along said beam from a cathode, a control grid,a screen grid, and an accelerating electrode, insulating rods spacedfrom said structure connected to and positioning said control grid,screen grid and said accelerating electrode with respect to each other,a centering device provided on said accelerating electrode forpositioning said electron gun within said neck portion, supporting meansprovided in the region of said control grid comprising an annular memberhaving project ng pins on its outer periphery which are impaled in saidinsulating rods and a glass stem member sealed to the end of said neckportion and provided with a plurality of stem lead members, three ofsaid stem lead members attached to said annular member for supportingsaid electron gun structure within said neck portion.

2. A cathode ray tube comprising an envelope having a neck portion, anelectron gun mc inted within said neck portion, said electron guncomprising a unitary structure comprised of a plurality of tubularshaped electrodes, said tubular shaped electrodes being provided withprojecting pins which are impaled in insulating rod members to align andposition the electrodes within said unitary structure, a stem memberprovided at the end of said neck portion for closing ofi said neckportion and supporting said electron gun within said neck portion, asupport ring positioned at the end of said electron gun adjacent saidstem member and of a larger diameter than the adjacent electrode member,said support ring also provided with projecting pins which are impaledin the insulating rod members and stem lead members provided in saidstem member and, secured to said support ring to support said unitarygun structure within said envelope.

3. A cathode ray tube comprising an envelope having a neck portion, anelectron gun positioned within said neck portion, said electron guncomprising a plurality of electrodes spaced along the axis of said neckportion, said electrodes provided with a plurality of projecting pinswhich are impaled in insulating rod members positioned along saidelectron gun structure to align and position the electrode members ofsaid electron gun in a unitary structure, support means provided at theend of said neck portion for mounting said electron gun within said tubeneck, said support means comprising a stem memher through which lead-insare provided for applying voltages to said electrode members, said stemmember provided with at least three stem support members projecting intothe interior portion of said neck portion, an annular support ringpositioned at the end of said electron gun adjacent said stem member,said support ring of a larger diameter than said electrode members, saidsupport ring provided with projecting pins which are impaled in saidinsulating rod members and having said stem support members secured tosaid ring to support the electron gun structure within said neckportion.

4. A cathode ray tube comprising a face plate, a flared portion and aneck portion, an electron gun provided within said neck portion forgenerating an electron beam to scan said face plate portion, saidelectron gun comprising a plurality of electrodes positionedsubstantially along the axis of said neck portion, the electrodes ofsaid electron gun structure secured together to provide a unitarystructure, said electrodes having a plurality of pins provided abouttheir outer periphery which are impaled in a plurality of insulating rodmembers, said rod members substantially parallel to the axis of saidneck portion, centering means provided at the end of the electron gunnearest said face plate for centering said electron gun within saidtubular neck, support means provided at the opposite end of said gun formounting said electron gun within said tubular neck, said support meanscomprising an annular ring coaxial with the electrode of: said gunfarthest from said face plate, said ring having pins thereon impaled insaid insulating rods, a stern member provided in said neck portion forclosing 01f the end of said neck portion and having a plurality of stemlead members which are secured to said ring to support the electron gunwithin the neck portion of said tube.

References Cited in the file of this patent UNITED STATES PATENTS2,464,076 De Gier Mar. 8, 1949 2,592,242, Campbell Apr. 8, 19522,808,527 McKenzie Oct. 1, '1957 2,810,851 Johnson Oct. 22, 19572,833,952 Hemphill May 6, 19 58

